The present invention relates to polyurethane gel foams and to the use thereof in modern wound treatment. In particular, the present invention relates to wound dressings comprising polyurethane gel foams for treating moderately to severely exuding wounds.
Polyurethane gel foams have been known for some time. For example, international application WO 88/01878 A1 describes self-adhesive polyurethane foams or polyurethane gel foams. These polyurethane gel foams are used as the wound contact layer in wound dressings.
Furthermore, hydrophilic foams made of polyurethane gel are described in the international applications WO 92/17518 A1 and WO 94/07935 A1. These foams are manufactured from at least one polyether polyol, at least one diisocyanate, water, accelerator and one or more superabsorbent polymers, wherein the components are mixed and possibly foamed by adding gases.
Moreover, international application WO 97/43328 A1 describes a self-adhesive polyurethane gel or polyurethane foam gel that is manufactured from an aliphatic diisocyanate, a polyol component, a stabilizer and reaction accelerators. These polyurethane foam gels do not contain a proportion of polysaccharides.
From U.S. Pat. No. 5,833,665 A, a dressing for fixing a catheter is known. The wound dressing comprises pillow wound dressing made of an isocyanate prepolymer and a biopolymer, which releases medication. The biopolymer might be, for example, pectin, gelatine, or algin.
Furthermore, international patent application WO 00/47241 A1 describes a polyurethane foam for use as a wound contact layer that is manufactured from an isocyanate component or an isocyanate prepolymer, water and alginic acid or a salt thereof. If necessary, a monohydric C1-C3 alcohol can be added to the reaction mixture. Because of the incorporation of alginic acid, this polyurethane foam exhibits an improved absorption capability.
In WO 01/62818 A1 it is suggested that, to manufacture a polyurethane pressure-sensitive adhesive, two polyols or any other materials that react with NCO groups be obtained from isocyanates, wherein the components reacting with the isocyanates differ from each other in that the first polyol component has a molar mass greater than 2000 and the second polyol component has a molar mass less than 2000.
Furthermore, European patent application EP 1923077 A1 describes a multiple-layer dressing having a wound contact layer made of a hydrophilic, self-adhesive polyurethane elastomer. The elastomer is manufactured from a diisocyanate prepolymer and a polymer polyhydroxyl component.
Overall, it can be ascertained here that the proposed polyurethane gel foams exhibit a permeability that is at least partially insufficient for wound exudate.
Based on the prior art, the object of this invention is to provide alternative and improved polyurethane gel foams and wound dressings manufactured therefrom for treating secreting wounds. In particular, the polyurethane gel foams should be suitable for use as a wound contact layer in modern wound management. A wound dressing manufactured with this polyurethane gel foam should further not have wound adhering properties and should also prevent maceration of the skin surrounding the wound.